Method of burning out barrels



Dec. 29, 1964 H. w. STRATFORD 3,163,134

METHOD OF BURNING OUT BARREL S Filed Nov. 4, 1963 3.5.1. A 3-5.4. I; l'

I z INVENTOR A/[PWTMSTMT WZ a EMA-MCI, 0/005 fizz-4S: A ar/037mm? $5M Am ATTORNEYS United States Patent Office 3,153,134 Patented Dec. 2%, 1 $64 This invention relates generally to the reclaiming of metal barrels or drums, and more particularly to a method for safely chairing or burning out combustible vaporproducing residue remaining on the interior surfaces thereof.

In reclaiming barrels or drums having removable lids, it is usually a safe and economical procedure to direct a flame thereinto through the open end or otherwise heat the barrel for charting residue remaining on the inside walls prior to cleaning. However, such burning out of barrels or drums provided with only a small opening or bung hole and containing combustible vapor-producing residue as from paint, lubricating oils, etc., is likely to be extremely dangerous. This is due to the explosive conditions produced by the mixin and confining ofsuch vapors with oxygen which has previously entered into the substantially empty barrel from the atmosphere. This situation has rendered the restoration of such barrels so hazardous that it has often been described as an economically unjustifiable operation.

The principal objects of the present invention are: to provide a safe and economical method for restoring or reclaiming barrels containing combustible vapor-producing residues, which method includes burning out; to pro vide such a method which includes prior treatment whereby the oxygen normally contained within the barrel is displaced by a non-combustible gas prior to the burning or heating operation; to provide such a method which in a preferred form utilizes only a relatively small inexpensive piece of solidified carbon dioxide or Dry Ice for displacing oxygen in the barrel; to provide such a method wherein considerable time may elapse between the oxy gen displacement step and the burning step without materially increasing the danger of explosion; and to provide such a method Which requires no specialized apparatus, using only existing exterior barrel burning equipment.

Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings wherein are set forth by way of illustration and example certain embodiments of this invention.

FIG. 1 is a side elevation of a residue-containing bung hole type barrel or drum with portions broken away showing the interior thereof and a piece of Dry Ice received thereinto.

FIG. 2 is a fragmentary partially schematic side elevation on a reduced scale showing a plurality of residuecontaining barrels inverted on a conveyor line and passing through oven apparatus containing equipment directing flames thereagainst.

FIG. 3 is a cross-sectional end elevation through the oven of FIG. 2 particularly showing the flames being directed against the exterior top and side surfaces of a barrel.

FIG. 4 is a side elevation of a barrel after passing through the oven with a portion broken away revealing charred residue chips being removed through the bung hole.

Referring to the drawings in more detail:

The reference numeral 1 generally indicates a metal drum or barrel of the type wherein the only opening ereinto is a bung hole 2. The barrel 1 is illustrated in FIG. 1 as having an interior coating or residue 3 of a material such as paint, lubricating oil, hydrocarbon chemicals, etc., of the type which may be charred into loose flakes or ash at high temperatures but tends to produce combustible vapors during such charring.

In accordance with a preferred form of this invention,

1 when the barrel 1 is in an upright condition, that is with the open bung hole 2 facing upwardly, a small piece 4 of solid carbon dioxide or Dry Ice is inserted through the bung hole and comes to rest on the bottom 5 of the barrel. For the purposes of this invention, it has been found that a piece of Dry Ice approximately the size of a 1-inch cube is suflicient for treating a standard SS-gallon drum.

The sublimation of the Dry Ice into gaseous carbon dioxide produces a displacement of the atmospheric gases contained in the barrel. Such gases, including the oxygen forming a part thereof, are urged out the bung hole 2 since the carbon dioxide is significantly heavier than nearly all gaseous fractions normally contained within the empty barrel, thus pushing them upwardly by expanding from below. Due to the relatively small bung hole open ing, the rate of diffusion of atmospheric gases back into the barrel is relatively small and, therefore, the carbon dioxide containing barrels can be safely stored upright for several hours before burning without danger of an explosively dangerous quantity of oxygen being reintroduced thereinto. If desired, the bung hole may be covered to further reduce the rate of difiusion.

The barrel is subsequently placed on a suitable conveyor 6 preferably in an inverted position, that is, with the bung hole 2 facing downwardly. The conveyor 6 is preferably of mesh or other suitable construction so as not to restrict the subsequent downward passage of gas therethrough as the barrel is heated. The barrel is then moved by means of the conveyor 6 into a furnace or oven 7 through a suitable entranceway 8. Within the oven 7, a framework 9 is provided along the path taken by the conveyor 6 and supports a plurality of spaced nozzles 10 adapted to direct flames 11 against the exterior surface 12 of the barrel for the purpose of heating the interior thereof. The nozzles 10 may burn any suitable fuel, for example, natural gas supplied by lines it). Upon heating the barrel, a large quantity of the carbon dioxide is expelled through the bung hole 2 due to the normal expansion thereof under elevating temperature; however, in many cases, the carbon dioxide is soon substantially entirely displaced by combustible vapors produced by the charring of the residue 3 within the barrel. The combustible vapors then follow the carbon dioxide out the bung hole 2. When exhausting from the bung hole 2, the combustible gases often ignite into a jet of flame as at 13, but due to the absence of oxygen within the barrel no explosive conditions are set up and the flame at 13 is harm lessly expended within the oven 7 and the products thereof are exhausted with the products of the flames 11 out a suitable exhaust stack 14.

When the barrel exits from the oven 7, it is preferably permitted to cool in the atmosphere, and during or after the cooling period it is often desirable to hammer or strike the outside surface thereof in order to help jar the resultant residue chips or ash 15 onto the inverted top 16 of the barrel where it can be removed by shaking, washing or other suitable means through the downwardly directed bung hole 2.

It is to be understood that while certain forms of this invention have been illustrated and described, it is not to be limited to the specific arrangement or steps herein described and shown except insofar as such limitations are included in the claims.

What is claimed and desired to be secured by Letters Patent is:

1. The method of heat cleaning of empty barrels and the like, said barrels being of the type having a hung hole for access thereinto and containing a residue onthe interior which-produces combustible vapors upon heating, said method comprising the steps of; placing the barrel in a position wherein the bung hole is generally uppermost and open, inserting a quantity of solidified carbonidioxide through the open bung hole sufiicient to upwardly displace substantially all atmospheric gases contained in the barrel upon sublimation thereof, heating the barrel to a temperature which chars said residue before substantial re-entry of atmospheric. gases into the barrel, and subjecting said barrel to impacts for separation and removal of the charred residue from the barrel.

2. The method of treating empty barrels and the like, said barrels being of the type having a bung hole for access therei'nto and containing a residue on the interior which produces combustible vapors upon heating, said method comprising the steps of; placing the barrel in'a position wherein the bung hole is generallyuppermost and open, inserting a quantit 1 of solidified carbon dioxide through the bung hole suificient to upwardly displace out the bung hole substantially all atmospheric gases contained in the barrel upon sublimation thereof, inverting the barrel containing the carbon dioxide but permitting free gas flow downwardly through the bung hole and directing flames against the exterior surface of the barrel for heating the interior surface thereof to a temperature which chars said residue before substantial re-entry of atmospheric gases into the barrel.

3. The method of heat cleaning empty metal barrels and the like, said barrels being of the type having a hung hole for access thereinto and containing a residue on the interior which produces combustible vapors upon heating, said method comprising the steps of; placing the barrel in a position wherein the bung hole is generally uppermost and open, inserting a quantity of solidified carbon dioxide through the bung hole suflicient to upwardly displace out the open bung hole substantially all atmospheric gases contained in the barrel upon sublimation thereof, inverting the barrel containing the carbon dioxide and permitting free gas flow downwardly through the open bung hole, directing flames against the exterior surface of the barrel for heating the interior thereof to a temperature which chars said residue, the heating of the barrel and residue therein-generating combustible vapors in said barrel, said vapors forcing the carbon dioxide through said open bung hole and following same to atmosphere, and igniting said vapors to burn same as they emerge from the barrel and mix with atmospheric gases.

References Cited by the Examiner UNITED STATES PATENTS 187,162 2/77 McMu-rtrie 2634. 2,656,008 10/53 Engel l1018 X 2,917,903 12/59 Stineman et a1. 15836 3,100,108 8/63 Selikson 263-4 JAMES W. WESTHAVER, Primary Examiner.

JOHN JCAMBY, Examiner. 

2. THE METHOD OF TREATING EMPTY BARRELS AND THE LIKE, SAID BARRELS BEING OF THE TYPE HAVING A BUNG HOLE FOR ACCESS THEREINTO AND CONTAINING A RESIDUE ON THE INTERIOR WHICH PRODUCES COMBUSTIBLE VAPORS UPON HEATING, SAID METHOD COMPRISING THE STEPS OF; PLACING THE BARREL IN A POSITION WHEREIN THE BUNG HOLE IS GENERALLY UPPERMOST AND OPEN, INSERTING A QUANTITY OF SOLIDIFIED CARBON DIOXIDE THROUGH THE BUNG HOLE SUFFICIENT TO UPWARDLY DISPLACE OUT THE BUNG HOLE SUBSTANTIALLY ALL ATMOSPHERIC GASES CONTAINED IN THE BARREL UPON SUBLIMATION THEREOF, INVERTING THE BARREL CONTAINING THE CARBON DIOXIDE BUT PERMITTING FREE GAS FLOW DOWNWARDLY THROUGH THE BUNG HOLE AND DIRECTING FLAMES 